Method of producing waterproof air transmissive fabrics for garments



Patented Dec. 26, 1939 UNITED STATES.

PATENT OFFICE.

METHOD OF PRODUCING WATERPROOF AIR. TRANSMISSIVE FABRICS 'FOR GAR- MENTS 'Emil Kmip and Fr nz Naef, Horn, Switzerland, assignors to the firm Textilwerk Horn A. G.,

Horn, Switzerland No Drawing. Application November 23, 1936, Se

rial No. 112,430. In Germany May 25, 1936 9 Claims. (01. 91-68) a lye-treatment, is then impregnated with an impregnating agent and subsequently subjected to a calendering process.

The object of the present invention is to materially simplify and improve a method of this kind: It has been found that as starting materials not only shrunk cotton fabrics enter into question but that likewise also non-shrunk cotton fabrics as well as other fibrous textiles are suitable for obtaining the desired result, such as wool, silk, artificial silk or the likefor textiles such as are known under the trade names of Vistra which is a mixture of staple fiber with cotton and Wollstra which is a mixture of staple fiber with wool. Furthermore. the reducing of the pores by shrinkage by means of an acid treatment can'be replaced by providing correspondingly small pores between the individual threads during the weaving. With a view to ascertaining the proper kind of fabric, we have made extensive tests with the result that, for example, for cotton a fabric say of the type /70, 40/40 has sufficiently small pores without requiring shrinking. It is to be noted that this mode of designating the fabric corresponds to that which is usual in the weaving industryin that the numerical data 70/70i ndicate that the weft as well as the warp threads of the fabric have the number 70, this number 70 defining a thread or yarn a hank length of '70 x 840 yards of which weighs one British pound. The latter data 40/40 indicate that in the warp and in the weft 40 threads are applied per A, of a French inch. By this designation the fabric will be clearly defined to persons familiar with fabrics. Such a fabric is provided with pores sufficiently small I for the present purpose without requiring to be shrunk by means of a lye-treatment.

It is obvious that the hereinafter described impregnating and fixing treatments can -be apk plied also to a cotton fabric the pores of which tion is materially improved in regard to resistivity against water and fastness to washing.

We have further found that fabric impregnated with parafiin solutions or other waterrepellent materials is-impaired to some extent, when repeatedly washed (say three times).

In order to avoid this drawback the fabric is impregnated with artificial resins, which are dissolved in volatile solvents, following the impregnation with water-repellent materials. These artificial resins are insoluble in water and consequently protect. the water-repellent impregnation against being removed by washing. By proportioning the amount of artificial resin incorporated in the fabric by this impregnation the air transmissive propertiesof the fabric can be varied to a certain extent. 7

Thus if, for example, 10 grams of artificial resin (solid) dissolved in grams of benzol are applied to 1 square metre of fabric the resultingfabric is appreciably transmissive for air. When, however, the amount of artificial resin applied to the square metre is increased to about 25 grams of artificial resin (solid) dissolved in 100 grams of benzol, a highly waterproof fabric is obtained the air transmissive properties of which are, however, slightly decreased.

For the impregnation several artificial resins are suitable, particularly those that are soluble in benzol, toluol or the like. During our tests we have found that the polymerisation products of vinyl acetate are particularly advantageous. These products are known in the color industry as ingredients for lacquer. According to the present invention for the purpose of applying such products to the waterproofing of textiles the polymerisation products of vinyl acetate are dissolved in benzol or toluol or other volatile solvents. Advantageously, to the solution a small percentage of parafin oil or else softening agents known per se such as, for example, synthetic esters of a high boiling point are added in order to prevent the layer of artificial resin becoming too brittle after drying. The impregnation is, advantageously, carried out in a trough through which the fabric web is passed via guide'rolls in a manner as usual in the textile industry. It may also be suitable to employ means for tensioning the fabric as this is likewisecustomary in the textile industry.

By effect of this impregnation with artificial resins the water-repellent materials are protected against being washed out, 'so that the fabric remains waterproof even after repeated washings. We have now found that a fabric impregnated with artificial resins is not fast against being washed out by dipping in water to the same extent as a fabric which has been impregnated, for example, with paraflin emulsions. The water does not readily trickle down and off of the fabric which has been simply impregnated with artificial resins. With a view to also ob taining high fastness of the fabric to dipping in water, the fabric may, after the impregnation with artificial resins, be once more impregnated with water-repellent material, particularly with paramnsolutions or emulsions. In this way a thin covering layer of parafiin for the artificial resin is produced which layer renders the fabric fast to dipping in every respect.

The fabric thus impregnated is then subjected to a calendering process. In this connection it has been experienced that it is advantageous to apply low temperatures since at higher temperatures the artificial resins become somewhat viscous. Therefore, the fabrics are calendered at a temperature of approximately 0. and at a pressure lower than usual for this purpose.

The method steps described above may be singly applied. Alternatively, a mode of procedure may be chosen so that the entirety of method steps herein described is-applied. In this case the method is carried out as follows:

A fabric composed of any desired fibrous material and having fine pores similar to a cotton fabric 70/70, 40/40 or a cotton fabric the pores of which have been decreased by shrinking it with caustic soda lye, is impregnated with waterrepellent material, advantageously with parafifin solutions or parafiin emulsions, and is then dried. Thereupon, the fabric is impregnated with artificial resins, which are dissolved in volatile solvents, so that approximately 10 to 25 grams of artificial resin (solid) are incorporated in every square metre of fabric. As particularly appropriate artificial resins the polymerisation products of vinyl acetate enter into question to the solutions of whichparaffin oils are added as softening agents.

The fabric impregnated with these artificial resins is impregnated once more, after drying, with water-repellent material, for example, paraffin solutions or emulsions and is then calendered at about 25 C. and below the usual pressures applied for this purpose.

We claim:

1. The method of producing lightweight, airtransmissive, waterproof fabric for garments having high resistivity to impairment of its waterproof property from the effects of washing, comprising impregnating a textile fabric having small pores substantially of the size of the pores of a fabric of the type 70/70, 40/40 with liquid paraflin in a quantity insufficient, when dry, to close the pores of the fabric, drying the paraflin to solid state, then impregnating same fabric with from about 10 to 20 grams per square meter of vinyl acetate artificial resin, then calendering the fabric at a temperature of about 25 0., at which temperature the paraffin and resin jointly will not become viscous so as to prevent spreading of the, impregnants and closing the pores of the fabric from the effect of calendering.

2. The method of producing lightweight, airtransmissive, waterproof fabric for garments having high resistivity to impairment of its waterproof property from the effects of washing,

- comprising impregnating a textile fabric having of a fabric of the type 70/70, 40/40 with liquid paraffln in a quantity insufiicient, when dry, to close the pores of the fabric, drying the paraflin to solid state,'.then impregnating said fabric with from about 10 to 20 grams per square meter of vinyl acetate artificial resin, then impregnating the fabric with paraffin in liquid state, and then calendering the fabric at a temperature of about 25 0., at which temperature the parafiin and resin jointly will not become viscous so as to prevent spreading of the impregnants and closparafiin in a. quantity insufficient, when dry, to

close the pores of the fabric, drying the paraflin to solid state, then impregnating said fabric with a volatile solvent solution of vinyl acetate artificial resin which leaves in the fabric, when dried, from 10 to 25 grams of the resin per square meter of the fabric, drying the resin solution, and calendering the fabric at a temperature of about 25 0., at which temperature the paraffin and resin jointly will not become viscous so as to prevent spreading of the impregnants and closing the pores of the fabric from the effect 01' calendering.

4. The method of producing lightweight, airtransmissive, waterproof fabric for garments having high resistivity to impairment of its waterproof property from the effects of washing, comprising impregnatinga cellulosic textile fabric having small pores substantially of the size of the pores of a fabric of the type 70/70, 40/40 with liquid parafiininaquantity insufiicient, when dry, to close the pores of the fabric, drying the parafiin to solid state, then impregnating said fabric with from about 10 to 20 grams per square meter of vinyl acetate artificial resin, then calendering the fabric at a temperature of about 25 0., at which temperature the parafiin and resin jointly will not become viscous so as to prevent spreading of the impregnants and closing the pores of the fabric from the effect of calendering.

5. The method of producinglightweight, airtransmissive, waterproof fabric for garments having high resistivity to impairment of its waterproof property from the effects of washing. comprising impregnating a cotton textile fabric having small pores substantially of the size of the pores of a fabric of the type 70/70, 40/40 with liquid paraffin in a quantity insufiicient,

when dry, to close the pores of the fabric, drying the paraffin to solid state, then impregnating said fabric with from about 10 to 20 grams per square meter of vinyl acetate artificial resin, then calendering the fabric at a temperature of about 25 0., at which temperature the paraffin and resin jointly will not become viscous so as to prevent spreading of the impregnants and closing the pores of the fabric from the effect of calendering.

6. The method of producing lightweight, airtransmissive, waterproof fabric for garments having high resistivity to impairment of its waterproof property from the effects of washing, comprising impregnating a wool textile fabric having small pores substantially of the size of the pores of a fabric of the type 70/70, 40/40 with liquid paraflin in a quantity insufficient, when dry, to close the pores of the fabric, drying the paraffin to solid state, then impregnating said fabric with from about to 20 grams per square meter of vinyl acetate artificial resin, then calendering the fabric at a temperature of about 25 C. at which temperature the paramn and resin jointly will not become viscous so as to prevent spreading 10 of the impregnants and closing the pores of the fabric from the effect of calendering. g

7. The methodof producing lightweight, airtransmissive, waterproof fabric for garments having high resistivity to impairment of its waterproof property from the effects of washing, comprising impregnating a silk textile fabric having small pores substantially of the size of the pores of a fabric of the type 70/70, 40/40 with liquid paraflin in a quantity insufficient,

when dry, to close the pores of the fabric, drying the paraffin to solid state, then impregnating said fabric with from about 10 to 20 grams per square meter of vinyl acetate artificial resin, then calendering the fabric at a temperature of about 5 C. at which temperature the paraffin and resin jointly will not become viscous so as to prevent spreading of the impregnants' and closing the pores of the fabric from theeifect of calender 111g.

o 8. The method of producing lightweight, airtran smissive, waterproof fabric for garments having high resistivity to impairment of its water proof property from the effects of washing, comprising impregnating a textile fabric having small pores substantially of the size of the pores of a fabric of the type 70/70, 40/40 with an emulsion of paraflln in a quantity insumcient, when dry, to

close the pores of the fabric, drying the parafiin emulsion to solid state, then impregnating said 5 fabric with from about 10 to 20 grams per square meter of vinyl acetate artificial resin, then calendering the fabric at a temperature of about 25 C., at which temperature the paraffin and resin jontly will not become viscous so as to pre- 14? vent spreading of the impregnants and closing the pores of the fabric from the effect of calendering.

9 The method of producing lightweight; airtransmissive, waterproof fabric for garments 15? having high resistivity to impairment of its waterproof property from the effects of washing, comprising impregnating a textile fabric having small pores substantially of the size of the pores of a fabric of the type /70, 40/40 with a solution of 

